-- -- TRIGGERS -- create table pkeys (pkey1 int4 not null, pkey2 text not null); create table fkeys (fkey1 int4, fkey2 text, fkey3 int); create table fkeys2 (fkey21 int4, fkey22 text, pkey23 int not null); create index fkeys_i on fkeys (fkey1, fkey2); create index fkeys2_i on fkeys2 (fkey21, fkey22); create index fkeys2p_i on fkeys2 (pkey23); insert into pkeys values (10, '1'); insert into pkeys values (20, '2'); insert into pkeys values (30, '3'); insert into pkeys values (40, '4'); insert into pkeys values (50, '5'); insert into pkeys values (60, '6'); create unique index pkeys_i on pkeys (pkey1, pkey2); -- -- For fkeys: -- (fkey1, fkey2) --> pkeys (pkey1, pkey2) -- (fkey3) --> fkeys2 (pkey23) -- create trigger check_fkeys_pkey_exist before insert or update on fkeys for each row execute procedure check_primary_key ('fkey1', 'fkey2', 'pkeys', 'pkey1', 'pkey2'); create trigger check_fkeys_pkey2_exist before insert or update on fkeys for each row execute procedure check_primary_key ('fkey3', 'fkeys2', 'pkey23'); -- -- For fkeys2: -- (fkey21, fkey22) --> pkeys (pkey1, pkey2) -- create trigger check_fkeys2_pkey_exist before insert or update on fkeys2 for each row execute procedure check_primary_key ('fkey21', 'fkey22', 'pkeys', 'pkey1', 'pkey2'); -- Test comments COMMENT ON TRIGGER check_fkeys2_pkey_bad ON fkeys2 IS 'wrong'; ERROR: trigger "check_fkeys2_pkey_bad" for table "fkeys2" does not exist COMMENT ON TRIGGER check_fkeys2_pkey_exist ON fkeys2 IS 'right'; COMMENT ON TRIGGER check_fkeys2_pkey_exist ON fkeys2 IS NULL; -- -- For pkeys: -- ON DELETE/UPDATE (pkey1, pkey2) CASCADE: -- fkeys (fkey1, fkey2) and fkeys2 (fkey21, fkey22) -- create trigger check_pkeys_fkey_cascade before delete or update on pkeys for each row execute procedure check_foreign_key (2, 'cascade', 'pkey1', 'pkey2', 'fkeys', 'fkey1', 'fkey2', 'fkeys2', 'fkey21', 'fkey22'); -- -- For fkeys2: -- ON DELETE/UPDATE (pkey23) RESTRICT: -- fkeys (fkey3) -- create trigger check_fkeys2_fkey_restrict before delete or update on fkeys2 for each row execute procedure check_foreign_key (1, 'restrict', 'pkey23', 'fkeys', 'fkey3'); insert into fkeys2 values (10, '1', 1); insert into fkeys2 values (30, '3', 2); insert into fkeys2 values (40, '4', 5); insert into fkeys2 values (50, '5', 3); -- no key in pkeys insert into fkeys2 values (70, '5', 3); ERROR: tuple references non-existent key DETAIL: Trigger "check_fkeys2_pkey_exist" found tuple referencing non-existent key in "pkeys". insert into fkeys values (10, '1', 2); insert into fkeys values (30, '3', 3); insert into fkeys values (40, '4', 2); insert into fkeys values (50, '5', 2); -- no key in pkeys insert into fkeys values (70, '5', 1); ERROR: tuple references non-existent key DETAIL: Trigger "check_fkeys_pkey_exist" found tuple referencing non-existent key in "pkeys". -- no key in fkeys2 insert into fkeys values (60, '6', 4); ERROR: tuple references non-existent key DETAIL: Trigger "check_fkeys_pkey2_exist" found tuple referencing non-existent key in "fkeys2". delete from pkeys where pkey1 = 30 and pkey2 = '3'; NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted ERROR: "check_fkeys2_fkey_restrict": tuple is referenced in "fkeys" CONTEXT: SQL statement "delete from fkeys2 where fkey21 = $1 and fkey22 = $2 " delete from pkeys where pkey1 = 40 and pkey2 = '4'; NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys2 are deleted update pkeys set pkey1 = 7, pkey2 = '70' where pkey1 = 50 and pkey2 = '5'; NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted ERROR: "check_fkeys2_fkey_restrict": tuple is referenced in "fkeys" CONTEXT: SQL statement "delete from fkeys2 where fkey21 = $1 and fkey22 = $2 " update pkeys set pkey1 = 7, pkey2 = '70' where pkey1 = 10 and pkey2 = '1'; NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys2 are deleted DROP TABLE pkeys; DROP TABLE fkeys; DROP TABLE fkeys2; -- -- I've disabled the funny_dup17 test because the new semantics -- -- of AFTER ROW triggers, which get now fired at the end of a -- -- query always, cause funny_dup17 to enter an endless loop. -- -- -- -- Jan -- -- create table dup17 (x int4); -- -- create trigger dup17_before -- before insert on dup17 -- for each row -- execute procedure -- funny_dup17 () -- ; -- -- insert into dup17 values (17); -- select count(*) from dup17; -- insert into dup17 values (17); -- select count(*) from dup17; -- -- drop trigger dup17_before on dup17; -- -- create trigger dup17_after -- after insert on dup17 -- for each row -- execute procedure -- funny_dup17 () -- ; -- insert into dup17 values (13); -- select count(*) from dup17 where x = 13; -- insert into dup17 values (13); -- select count(*) from dup17 where x = 13; -- -- DROP TABLE dup17; create sequence ttdummy_seq increment 10 start 0 minvalue 0; create table tttest ( price_id int4, price_val int4, price_on int4, price_off int4 default 999999 ); create trigger ttdummy before delete or update on tttest for each row execute procedure ttdummy (price_on, price_off); create trigger ttserial before insert or update on tttest for each row execute procedure autoinc (price_on, ttdummy_seq); insert into tttest values (1, 1, null); insert into tttest values (2, 2, null); insert into tttest values (3, 3, 0); select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 2 | 2 | 20 | 999999 3 | 3 | 30 | 999999 (3 rows) delete from tttest where price_id = 2; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 3 | 3 | 30 | 999999 2 | 2 | 20 | 40 (3 rows) -- what do we see ? -- get current prices select * from tttest where price_off = 999999; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 3 | 3 | 30 | 999999 (2 rows) -- change price for price_id == 3 update tttest set price_val = 30 where price_id = 3; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 2 | 2 | 20 | 40 3 | 30 | 50 | 999999 3 | 3 | 30 | 50 (4 rows) -- now we want to change pric_id in ALL tuples -- this gets us not what we need update tttest set price_id = 5 where price_id = 3; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 2 | 2 | 20 | 40 3 | 3 | 30 | 50 5 | 30 | 60 | 999999 3 | 30 | 50 | 60 (5 rows) -- restore data as before last update: select set_ttdummy(0); set_ttdummy ------------- 1 (1 row) delete from tttest where price_id = 5; update tttest set price_off = 999999 where price_val = 30; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 2 | 2 | 20 | 40 3 | 3 | 30 | 50 3 | 30 | 50 | 999999 (4 rows) -- and try change price_id now! update tttest set price_id = 5 where price_id = 3; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 1 | 1 | 10 | 999999 2 | 2 | 20 | 40 5 | 3 | 30 | 50 5 | 30 | 50 | 999999 (4 rows) -- isn't it what we need ? select set_ttdummy(1); set_ttdummy ------------- 0 (1 row) -- we want to correct some "date" update tttest set price_on = -1 where price_id = 1; ERROR: ttdummy (tttest): you can't change price_on and/or price_off columns (use set_ttdummy) -- but this doesn't work -- try in this way select set_ttdummy(0); set_ttdummy ------------- 1 (1 row) update tttest set price_on = -1 where price_id = 1; select * from tttest; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 2 | 2 | 20 | 40 5 | 3 | 30 | 50 5 | 30 | 50 | 999999 1 | 1 | -1 | 999999 (4 rows) -- isn't it what we need ? -- get price for price_id == 5 as it was @ "date" 35 select * from tttest where price_on <= 35 and price_off > 35 and price_id = 5; price_id | price_val | price_on | price_off ----------+-----------+----------+----------- 5 | 3 | 30 | 50 (1 row) drop table tttest; drop sequence ttdummy_seq; -- -- tests for per-statement triggers -- CREATE TABLE log_table (tstamp timestamp default timeofday()::timestamp); CREATE TABLE main_table (a int, b int); COPY main_table (a,b) FROM stdin; CREATE FUNCTION trigger_func() RETURNS trigger LANGUAGE plpgsql AS ' BEGIN RAISE NOTICE ''trigger_func() called: action = %, when = %, level = %'', TG_OP, TG_WHEN, TG_LEVEL; RETURN NULL; END;'; CREATE TRIGGER before_ins_stmt_trig BEFORE INSERT ON main_table FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func(); CREATE TRIGGER after_ins_stmt_trig AFTER INSERT ON main_table FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func(); -- -- if neither 'FOR EACH ROW' nor 'FOR EACH STATEMENT' was specified, -- CREATE TRIGGER should default to 'FOR EACH STATEMENT' -- CREATE TRIGGER before_upd_stmt_trig AFTER UPDATE ON main_table EXECUTE PROCEDURE trigger_func(); CREATE TRIGGER before_upd_row_trig AFTER UPDATE ON main_table FOR EACH ROW EXECUTE PROCEDURE trigger_func(); INSERT INTO main_table DEFAULT VALUES; NOTICE: trigger_func() called: action = INSERT, when = BEFORE, level = STATEMENT NOTICE: trigger_func() called: action = INSERT, when = AFTER, level = STATEMENT UPDATE main_table SET a = a + 1 WHERE b < 30; NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = ROW NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = ROW NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = ROW NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = ROW NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = STATEMENT -- UPDATE that effects zero rows should still call per-statement trigger UPDATE main_table SET a = a + 2 WHERE b > 100; NOTICE: trigger_func() called: action = UPDATE, when = AFTER, level = STATEMENT -- COPY should fire per-row and per-statement INSERT triggers COPY main_table (a, b) FROM stdin; NOTICE: trigger_func() called: action = INSERT, when = BEFORE, level = STATEMENT NOTICE: trigger_func() called: action = INSERT, when = AFTER, level = STATEMENT SELECT * FROM main_table ORDER BY a, b; a | b ----+---- 6 | 10 21 | 20 30 | 40 31 | 10 50 | 35 50 | 60 81 | 15 | (8 rows) -- Test enable/disable triggers create table trigtest (i serial primary key); NOTICE: CREATE TABLE will create implicit sequence "trigtest_i_seq" for serial column "trigtest.i" NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "trigtest_pkey" for table "trigtest" -- test that disabling RI triggers works create table trigtest2 (i int references trigtest(i) on delete cascade); create function trigtest() returns trigger as $$ begin raise notice '% % % %', TG_RELNAME, TG_OP, TG_WHEN, TG_LEVEL; return new; end;$$ language plpgsql; create trigger trigtest_b_row_tg before insert or update or delete on trigtest for each row execute procedure trigtest(); create trigger trigtest_a_row_tg after insert or update or delete on trigtest for each row execute procedure trigtest(); create trigger trigtest_b_stmt_tg before insert or update or delete on trigtest for each statement execute procedure trigtest(); create trigger trigtest_a_stmt_tg after insert or update or delete on trigtest for each statement execute procedure trigtest(); insert into trigtest default values; NOTICE: trigtest INSERT BEFORE STATEMENT NOTICE: trigtest INSERT BEFORE ROW NOTICE: trigtest INSERT AFTER ROW NOTICE: trigtest INSERT AFTER STATEMENT alter table trigtest disable trigger trigtest_b_row_tg; insert into trigtest default values; NOTICE: trigtest INSERT BEFORE STATEMENT NOTICE: trigtest INSERT AFTER ROW NOTICE: trigtest INSERT AFTER STATEMENT alter table trigtest disable trigger user; insert into trigtest default values; alter table trigtest enable trigger trigtest_a_stmt_tg; insert into trigtest default values; NOTICE: trigtest INSERT AFTER STATEMENT insert into trigtest2 values(1); insert into trigtest2 values(2); delete from trigtest where i=2; NOTICE: trigtest DELETE AFTER STATEMENT select * from trigtest2; i --- 1 (1 row) alter table trigtest disable trigger all; delete from trigtest where i=1; select * from trigtest2; i --- 1 (1 row) -- ensure we still insert, even when all triggers are disabled insert into trigtest default values; select * from trigtest; i --- 3 4 5 (3 rows) drop table trigtest2; drop table trigtest;